JUNE,1915. ’ MONTHLY WEA!LWER REVIEW. 281 - -.& ?/-. j ‘11 I . That the sumem of Paris are so very much cooler WEATHER AND RAD^ EMA~YATIONAT IYIANILA,P. I. than those of Reno will probabl be a surprise to tlir Durin the year July, 1913, to Jul , 1914, J. R. Wright French residents of Reno, of wx om there are a large and 0. fi. Smith, of Manila, P. I ape continued their number. Now, in Reno, intolerably hot days are observations on the amount of raTdliumK emanation in the unknown, probably because on those days when the atmosphere of that city, with the object of determining temperature esceeds 90’ F., the air is alwaj- exceedingly more definitely to what extent the amount of radium dry. To one who has lived in the Middle or Southern emanation in the air is dependent on weather conditions. States for two or more years, Reno’s summers are The details o€ the work are presented in the “Physical imitalion summers, merely. Nobody ever suffers from Review” for June, 1915, and we reprint below the general the effects of the lieat in Reno. On inany evenings in conclusions reached. summer hglit coate and wraps are worn 011 Reno’s streets. Now, since the avera e seasonal escess (on a basis of Swwimry of iusults. 86OF. or 30’C.) is 3Oh. at Paris, us against 17i’F. st Reno, it follows that the average Paris sumnier niust be 1. The variation of the amount of radium emmatipxi cold. Perhaps this is one reason why thoussnds of in the atmosphere ut Man& has been determined for a Louisianians and other southerners are so fond of spend- period of about 18 months. The annual and diurnal i the summer season in the capital of France. variation has been studied in connection with the prin- itseems to me that comparative summer-temperature cipal nieteorological factors. The effect of weather con- tables pre ared in the manner suggested by hgot for ditions on the rate ut which radium eninnation is exhaled all the eather Bureau stations in the United States from the surface of the ground has been investi ated which claimwp to be summer resorts should prove both with the object of detcrinining .its coiinection witf the interesting and valuable. It would be high1 interesting, t?nianation content of the atnios here. The relation for instance, to corn are the summers of As Tieville, Luke behveen tho rate of eshalation anf the radioactivity of Minnetonka, ColoraB o Springs, Reno, and San Frwciaco. soil gas at different de ths has also been investigated. At first thought, it seemed to me that the Angot 2. The variation of tYl e radium-emanation content of method would enable us to find a numerical expression the atmosphere has been found to follow cpite closely for “discomfort degrees” in summer, but after looking the variations in rainfall and Rind movement. [See into the subject more closely it occurred to me that Table 1.3 Tho ratio of the maximum to the minimum without the humidity element of the climate, $his could for the year was found to be approximately as 10 to 1. not be. To those who are familiar with the climates The mean of the monthly means gives for the radium of San Francisco and Reno, it must be evident that a equivalent of the emanation per mbic meter of air a temperature of 86’F. and a relative humidity of 82 per value of 71.0~10-~*grams. The manth of January cent stand for a greater number of discomfort units shows the hghest monthly mem for the radium-ema- than do a temperature of 86OF. and relative humidity of nation content, the minimum value for the rainfall, 25 per cent. (The humidities cited are the mean 5 p. m. and a low value for the total wind movement. The values for San Francisco and Reno, respectively, for month of July gives the lowest monthly mean for the emanation content, the maximum value. €or the July.) Indeed, the first would be a very warm, o pres- rainfd, sive day, while the latter would be a cornfortab% and hest total wind movement. Every other moderately warm one. I think that the Anwt tables monthand the of 9t e year shows a very similar relation. No would reach their highest degree of usefukess and direct connection bas been discovered between the convenience if,. in some manner, the relative humidity emanation content and atmospheric pressure or humidity. were made an mte a1 part of such tables. If this were The effect of the direction of the wind seems at best very done in the case oY Paris and Reno, perhaps the Paris indefhi te. ~ummerswould not turn out to be so cold as the An ot TABLEI.-Annual 71Urialion of the rodiatwn-einmmtib eontent at Manila. table wit7wzd humidities seems to make them out. dy [Number In brackets in last colnmn shows the number of ob.sprvations enbring hta not use the mean relative humidity at the observation the monthly mean.] .... __ _ .... _.. ~---.-- next following the occurrence of the daily maximum ! I I temperature? This, I believe, would be sufficiently i i accurate for practical purposes. Or, in order to avoid I the integrating of tem eratures and humidities, why not UBB the mean wet-bul f temperature at the observation next followin the time of occurrence of the maximum temperaturesf In other words, the ‘‘sensible tempera- -,” called. so 1913. ’ MSi July ...... 756, 2(i 86.2 6’10.6 The importance of humidity data in this connection August ...... 756.93 87.0 349.1 may be understood by considering some of the climatic September...... 757.67 81.4 3a.5 October...... 768.61 83.4 110.7 conditions that entered into the make-up of an usudy November- ...... 81.7 31.1 warm day in Reno, namely, Au st 5,1914. At 1 p. m., Dfm.uk...... 80.9, 37. a the thermometer stood at 98°~(370C?.)- and there was 1914. i I i L 3-dean-hour breeze blo from the southeast at January...... 76.a ’ 4,925.5 3.5 February...... 2 73.8 5.a55.5 j 7.3 the time. At the 5 p. m.T o servation following, or March ...... 760.77 1 08.6 8 344 0 6.1 A il...... 780.17 rn.8 s’szl:o! 53.4 four hours later, the webbulb temperature was 62”F., ?&...... 758-42 72.8 6’137.5 84.0 urd the relative humidity onl 18 per cent. was Jupe ...... 757.621 81.7 6:714.01 367.9 The sky July ...... I...... eloudless. These are typica9 warm-weather conditions I and the reader familiar with wet-bulb tem eraturea and ..I...... dative humidity data will readily uncr erstand why intolerably hot, muggy weather and sunstrokes are unknown in Reno.

Unauthenticated | Downloaded 09/26/21 11:47 PM UTC =a MONTHLY WEATEER REVIEW. JUNE,1916 3. A decided diurnal variation has been found to exist, designated by certain official meteorologists as being the emanation content being considerably greater during “as useless as possible’’ and “wit,hout either scientXc the ni ht than during the day. Observations for t91ie or practical value of any kind.” Esperience alone can intern3 from 11 p. ni. to 5 a. m. ai-e a mea? vtilue decide whether or no tohese crit,icisms are exagger- 3.31 times greater than the nieaii vn7 ue for t,he interval ated. from 11 a. m. to 5 p. m. This variation lias been found Guilbert’s me t,liod has now been applied in forecasting to be closelv related to the variation in the totnl wind for a Parisian journal since October 1, 1913, with the movement during the period, a high value of tlie wind result that the proportion of verifications has been SO per movement corresponding to a lorn due of the enimi- cent. During the winter seiiiest,er of 1913-14 this pro- tion content. portion rose t.0 86 per cent; while the proportion of veri- 4. The rate at which radium emanation is eslisled hcations rose to 89 per cent for those predictions essen- from the surface of the ground shows a decided decrease tially peculiar to his method, viz, t.he changes in the after periods of heavy rain. This decrease has been barometric depressions resulting in their intensifica- found in some cases to be almost 60 per cent of the rate tion, weakening, or disappearance. of exhalation for fair weather. The relation of cause to effect as established by the 5. The radium-emanation content of soil gas has been author between the force-direction of the wind and the determined for depths of 30, 70, and 120 cm., consecutive variation in the bnronietric pressure has tively, and the variation with weather conditions stureTec- id. roved so exact that it has been possible in many of his The variation of the radioactivity of t-he gibs froni the 30 forcasts to designate (1) the relat,ive iiiiportance of the cm. pipe was found to follow closely the variation in tshe future barometric change, (21 it,s location, (3) its limits, emanation exhaled, a decrease in the eshdatiou resultin_ and (4) even the name of tho station where the baro- in a corres ondin increase in the emanation content o7 metric rise (hausse baroni6trique) will attain its niaxi- the groun%gas. %he 70 cm. and 120 cm. yips showed mum. Thus, among all t,he stations in France, for only slight variations with the weatshercoli( itions. The usample, the author has been able to designate the avera e vdue of the emanation content for tshe gas col- occurrence of this maximum as now at Nantes, now at lectecffrom the 120 cm. pipe ww found to be 304.5~ Nice, or Paris, or Charleville, or at Havre, etc. yam per liter, or over 4,000 times the mean This “new method” forecasts every meteorological value or at.mospheric air. The mean value for the 3) phenomenon-rain and wind, tem erature, fog, thunder- cm. pipe WM only about8one-seventli t-hh;itfor t,he 130 etorms, etc.-simultaneously wit{ its principal cause, cm. pipe. the pressure change. The new method is, therefore, not merely ractical and utilizable but also scientific, mTEOROLOGICAL PAPERS PRESENTED AT THE &recast is made according to principles and HaVRE XEETING OF THE FRENCH ASSOCIATION. rules€Iince esta lished on c.onstant facts; nioreover, the rules At the 43d session of tmlieAssociation Frangaise pour may be applied by every meteorologist. A method l’draucement des Sciences, held at Havre in July, 1914, that during 21 months has erniitt,ed a daily forecast of atmospheric phenomena w\ ich meteorological science does not even attempt to foresee, must be regarded as a step in advance and ought to ut an end to the existin empiricism of official meteor07 ogical forecasts.-cabri5 Gudbert. Barogram and thermogram in. relation to cosmical phenomena.-The study of nebulae leads the author to RPforestation. and (I occuZt ” condenscrtions.-An abuiid- ant and regular supply of water is the vital essential of the su position that the combustion phenomena [in nebulsef) further the escape of gaseous masses which inland navigation, of the “ white coal” [waterpower] supply, and of a iculture. The “occult” condensations resemble the matter composing the stars, and that these dew and white rost, are not recorded by the raingsge masses become residual matter in interstellar space. f” When comets approach the sun (i. e., approach their but the supplement the rainfall with H quantity of water w%ich is controlled and redatetl in advance of erihelion) they under o uite irregular variations in its preci itatioii and which woulx be considerably in- form and brilliancy; t8% ey ave been observed (More- house) to give off explosions and to be destroyed creased YIy reforestation. For the quantity of frost even (givre) coating a tree at the close of a clear winter niglit (Bi6la) by an explosion. All these phenomena are is much greater than the quantit that collected dunng explicable only as due to the influence of an exterior the same night on a piece of nal ed ground whose area gaseous medium. Therefore, he concludes that the equsls that of the projection of the tree. lteforesta- mhrplanetary spaces of the solar nebulosity, as well as tion, already serving as an element in the control of of the others, contain residual gases. the water supply, may therefore be employed to in- This conce t seems to furnish an explanation of crease the supply of water under man’s control, and it meteorolo cap phenomena. While preparing for Le is desirable to determine the extent to wliich reforesta- Temps (F- aris) the dail temperature- and presswe tion can contribute. curves observed at the og servatory Tour Saint-Jacques After discussion, the section of the Association resolved in Paris, there was noticed a certain parallelism between that we should undertake studies designed to determine these simultaneous curves. This parallelism could .be the degree to which reforestation can su plement the very sim ly explained by referring it to the risin and water sup ly b thus reinforcing the “occuF t” condensrtr falllng oP that u per atmospheric stratuni calles the tions, suc%I aa ew and frost.-Pcrzd Descombtx “stratosphere.” ft then becomes necessary t.o seek the Weather forecasts by Guilbert’s rules.-The author general cause of atmospheric variations in the region called attention to the circumstance that his rules for above that stratum by ascribing them to the passage forecasting (Principes)’ as published in 1891 have been of independent gaseous 11in~s~wthat ha pen to come into contact [with t.li.c! c:irr,ii’s abmospP iere] and me influenced by the t-errestriiil rotation.

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